For all 16 primary osteosarcomas, both biopsy and resection specimens were immunohistologically stained using antibodies specific to VEGF and CD31, in order to investigate the clinical significance of angiogenesis in osteosarcoma and the effects of chemotherapy including HDMTX in neo-vascularization (Figures 1, 2). The gene discussed is VEGFA; the disease is osteosarcoma.